1. Field of the invention:
The present invention generally relates to a rotary piston engine and, more particularly, an improvement of a rotary piston engine of the type comprising a casing composed of a center housing having a trochoidal inner peripheral surface and side housings closing opposite ends of said center housing. A polygonal rotor adapted to rotate eccentrically in said casing with its apex seals provided at its apex edge portions contacts said inner peripheral surface of said center housing and with its corner seals provided at apex side portions and side seals provided to extend between two adjacent apex portions contacting inner walls of said side housings, so that volume variation of operating chambers defined by said casing and said rotor effects suction, compression, combustion, expansion and exhaustion strokes of operating fluid.
Conventionally, when an air or fuel injection opening is provided to open to an operating chamber space performing suction and compression strokes in a rotary piston engine of the aforementioned type so as to effect supercharging or direct fuel injection, there has been a problem in that if the opening is arranged to open to the inner peripheral surface of the center housing, through blowing of operating gases from one operating chamber to an adjacent operating chamber occurs by way of said opening at the moment said opening is traversed by the apex seal, causing lowered output of the engine and deterioration of fuel consumption rate. An alternative structure of providing said air or fuel injection opening at the wall of the side housing has not solved the blow-by gas problem since a similar through blowing of operating gases is generated by way of the opening when it is traversed by the corner or side seal, causing a droppage in the engine output power and deterioration in the fuel consumption rate.